My original point was that the feminists would have had better luck keeping their abortion privileges if men had something to lose as well.

Nah, even then, 3rd trimester abortions are an impossible sell to the vast majority of people. They'd have a better chance of keeping their abortion rights if they were opened to compromise to 1st trimester, with exceptions if the mother's life is at risk in the case of rape. That's where you get the most support, basically, what they have in Europe in most places.